The objectives for this project are: 1) to study the responses to controlled thermal and mechanical stimuli from cortical neurons in the second somatic sensory, insular and posterior insular regions in primates; 2) to study the connections of physiologically defined portions of these cortical regions with autoradiographic and retrograde cell labeling techniques and, 3) to re-examine the neural responses from this cortex in awake, behaving animals conditioned to discriminate tactile or painful thermal stimuli. It is expected that these studies will help to define the cortical locus for pain and temperature sensations since these cortical regions receive inputs from portions of the thalamus known to receive projections from the spinothalamic tract.